Current practices use gas chromatography (GC) to periodically sample natural gas to determine the chemical composition within a gas collection and transmission facility. For example, gas chromatography is often performed on a monthly or quarterly basis to determine the health of an individual well or field. These samples are then used to determine the quality, energy content, or pricing associated with the gas delivered from that well or field. However, changes in the gas content, for the better or worse, may result in unrealized profits from a well or field. In the case of declining quality, penalties may be imposed on the supplier by delivering product from a field that does not meet the previously stated product requirements. Thus, using only one sample to describe the quality of the gas for an entire quarter is unrealistic.
In another instance, these samples may be taken at a single gathering location which pools gases supplied from a number of wells or fields. As not all the wells may be on service at the time of the sample, the removal from service of a high energy well may adversely impact the measured quality. When the high energy well is returned to serve, the output from the gathering location may then be undervalued because for an entire quarter or until the next periodic sample. This is because the high energy content is not considered.
Additionally, the potentially large latency between samples may result in undetected rising levels of contaminants such as hydrogen sulfide, carbon dioxide, water, nitrogen, and other like contaminates that do not contribute to the energy content of the gas. This may result in the gases exceeding the specified levels during the periodicity between samples. This in turn may result in damage to processing or manufacturing equipment and fines for the supplier.